81955245 has 8 divisors (see below), whose sum is σ = 131128416. Its totient is φ = 43709456.

The previous prime is 81955243. The next prime is 81955253. The reversal of 81955245 is 54255918.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81955245 - 2¹ = 81955243 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81955241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2731827 + ... + 2731856.

It is an arithmetic number, because the mean of its divisors is an integer number (16391052).

Almost surely, 2^81955245 is an apocalyptic number.

It is an amenable number.

81955245 is a deficient number, since it is larger than the sum of its proper divisors (49173171).

81955245 is a wasteful number, since it uses less digits than its factorization.

81955245 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5463691.

The product of its digits is 72000, while the sum is 39.

The square root of 81955245 is about 9052.9136193824. The cubic root of 81955245 is about 434.3690946526.

It can be divided in two parts, 8 and 1955245, that added together give a triangular number (1955253 = T₁₉₇₇).

The spelling of 81955245 in words is "eighty-one million, nine hundred fifty-five thousand, two hundred forty-five".